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West Contra Costa Sanitary Landfill

Construction Quality Assurance Engineering for the

1996 through 2001 and 2007 through 2010 Final Capping Project, Class II Sites

Client: West Contra Costa Sanitary Landfill, Incorporated

Questa performed Construction Quality Assurance Engineering for the final capping of approximately 100 acres of landfill from 1996-2001, and 2007-2009. CQA work completed included pre-construction laboratory testing of proposed cap materials, coordination with regulatory agencies, observations and testing during construction including field density and moisture content testing to verify compaction and moisture conditioning, verification of fill thickness for the foundation, barrier and vegetative layers, laboratory soils testing of the soils used as cap materials including permeability, maximum dry density, optimum moisture content, particle size analysis, and Atterberg limits. Database management of the field and laboratory testing results and presentation of data in a final summary report for submittal to permitting agencies was also performed.